Five activists were arrested and charged with trespassing Monday morning after chaining themselves together and blocking the entrance to a KCBX Terminals Co. petroleum coke facility on Chicago's southeast side.

The protesters sat side by side, first on the asphalt driveway and then on bright blue gym mats carted in by their supporters. Their hands were hidden inside plastic tubes wrapped in duct tape, designed to prevent police from separating them or moving them easily. A line of 18-wheelers idled across the street during the blockade, unable to enter or exit the facility.

Robin Amer

Police arrest Rev. Jim Galuhn of the East Side United Methodist Church.

But the environmentalists—members of the umbrella group Southeast Side Coalition to Ban Petcoke—traded their makeshift hand locks for actual handcuffs after police placed them under arrest.

Two protesters who had chained their hands inside a cement-filled barrel and parked themselves in front of a separate entrance were not arrested.

These efforts represent an escalation of tactics in a more than two-year struggle to force pet coke out of Chicago.

"During our last meeting with the Department of Public Health we were told we need to continue to make 311 calls and make formal complaints," said protester Kate Koval. "That's what we've done for the last two years and I'm over it. We needed to have a more drastic plan."

Pet coke is an oily black dust produced by the ton as sludgy tar sands oil is refined into liquid gasoline. Whiting, Indiana, is home to one of the nation's largest coking facilities; Chicago is home to two facilities that receive pet coke from the Whiting refinery and store it until it can be shipped out to corporate customers who burn it as fuel or use it to power energy-intensive manufacturing processes such as aluminum or cement making. Both Chicago facilities are operated by Koch brothers-controlled KCBX.

Since August 2012, neighbors have complained of pet coke dust blowing off the mountain-high pet coke piles and into their homes and backyards. City, state, and federal officials responded in kind: Chicago banned the storage and transfer of pet coke through the northernmost of the two facilities earlier this year; state's attorney general Lisa Madigan has filed separate complaints against both facilities; and U.S. senator Dick Durbin and U.S. representative Robin Kelly introduced legislation in July asking for a comprehensive study of the health effects of pet coke.

KCBX had previously said it would remove the pet coke piles from its south site by next summer, but has not addressed the transfer of pet coke through the facility. It uses water canons to hose down the pet coke piles and suppress dust from blowing into adjacent neighborhoods.

The protesters were released Monday afternoon. All five are scheduled to appear in Cook County Court on December 23. In a statement, KCBX spokesman Jake Reint said the company has "always sought to operate our facility with the utmost respect for our neighbors and the environment, and that remains the case today."